ANSI Previewer

ANSI Color styling and previewer for your text editor.

Forked from iliazeus/vscode-ansi and enhanced with more complete ANSI escape code and additional function support.

Screen.Recording.2025-09-20.at.09.41.03.mov

Basic usage

Select the ANSI Text language mode to highlight text marked up with ANSI escapes. Files with the .ans and .ansi extensions will be highlighted by default.

Run the ANSI Text: Open Preview command for the prettified read-only preview.

Clicking the preview icon in the editor title will open the preview in a new tab. Alt-click to open in the current tab.

The extension fetches the colors from the current theme and aims to look as good as the built-in terminal.

Supported ANSI escape codes

Enhanced Support (v1.2.0+): This extension now supports a comprehensive range of ANSI escape sequences including:

• SGR (Select Graphic Rendition): Colors, text formatting (bold, italic, underline, etc.)
• Cursor Control: Position (H, f), movement (A-G), save/restore (s, u)
• DEC Private Modes: Terminal behaviour control (?...h/?...l) for cursor visibility, mouse tracking, alternate screen
• Screen Manipulation: Erase sequences (J, K), scroll control (S, T)
• OSC Commands: Window titles, color palette control, clipboard operations
• Character Sets: ASCII, line drawing, and international character sets
• Device Queries: Status reports and device attributes

See ENHANCED_ANSI_SUPPORT.md for complete documentation of supported sequences.

Visual Examples

Basic colors and formatting:

8-bit colors:

24-bit colors:

FAQ

• Can files automatically be set to ANSI language mode?

  You can configure automatic ANSI language mode for files matching specific glob patterns. By default, .ans and .ansi files will automatically be set to ANSI language mode when opened, enabling escape sequence highlighting.

  You can customize this behaviour in VS Code settings using gitignore-style patterns:

  {
    "ansiPreviewer.autoLanguageModeFiles": [
      "**/*.ans",
      "**/*.ansi",
      "*.log", // All .log files in any directory
      "logs/*.txt", // .txt files in logs folder
      "output.txt", // Specific filename
      "build/**" // All files in build directory
    ]
  }

  Pattern support:

  • *.log - matches .log files in any directory (same as **/*.log)
  • logs/*.txt - matches .txt files only in logs folder
  • build/** - matches all files in build directory and subdirectories
  • output.txt - matches files named exactly output.txt

  Set it to an empty array [] to disable automatic language mode setting entirely.